ABSTRACT: OBJECTIVE: To assess the macular retina and choroidal thickness change in patients with obstructive sleep apnea-hypopnea syndrome (OSAS) with no significant symptoms and pathological changes in the fundus using spectral domain-optical coherence tomography. METHODS: This prospective, observational case-control study consisted of 53 eyes of 53 patients with OSAS and 12 eyes of 12 age-matched controls. Macular and choroidal thicknesses were measured by optical coherence tomography. RESULTS: The foveal and nasal macular thicknesses were significantly different between four groups (P=0.001, P=0.016). The foveal thickness of the control group was significantly thinner than that of the severe group (P=0.000). The nasal macular thickness of the control group was significantly thinner than that of the severe group (P=0.008). A significant correlation was found between oxygen desaturation index (ODI) and macular center thickness (r=0.357, R(2)=0.127, P=0.004), with an ODI coefficient of 0.457 (P=0.004). Similarly, a significant correlation was found between ODI and nasal macular thickness (r=0.265, R(2)=0.070, P=0.033), with an ODI coefficient of 0.233 (P=0.033). The subfoveal choroidal thickness was significantly different among the groups (F=3.657, P=0.017). The subfoveal choroidal thickness of the severe group was significantly thinner than that of the control group, mild group, and moderate group (P=0.023, 0.006, and 0.036, respectively). The choroidal thickness 1 mm nasal to the fovea was significantly different between the groups after correcting for age and diopter (F=3.411, P=0.023). The choroidal thickness 1 mm nasal to the fovea was significantly thinner in the severe group compared with the control group and mild group (P=0.013 and 0.010, respectively). Choroidal thickness was significantly correlated with diopter (r=0.520, R(2)=0.270, P<0.001), with a coefficient of 0.327 (P<0.001), and with ODI (r=0.520, R(2)=0.165, P=0.001), with a coefficient of -0.370 (P=0.001). CONCLUSIONS: OSAS patients showed decreased foveal and nasal macular thickness, similar to the subfoveal and nasal choroidal thickness. These findings suggest that, because of intermittent hypoxia, OSAS might change the retinal and choroidal blood supply.